Casing cutter



Feb. 21, 192s.

R. A. LINCOLN CASING CUTTER Filed Jan. 19. 1926 2 Sheets-Sheet 1 Feb. 2l, 1928.

R.y A. LINCQLN CASING CUTTER Filed Jan. 19. 1926 2 Sheets-Sheet 2 HH /M' atto? um# Patented Feb. 21, 192s.,

UNITED STATES 1,660,228 PATENT oFFlcE'.

ROBERT A. LINCOLN, OF TONKAWA, OKLAHOMA, ASSIGNOR 0F ONE-HALF TO AMERI- CAN IRON & MACHINE WORKS, INC., OF TONKAWA, OKLAHOMA, A CORPORATION or OKLAHOMA.

CASINO CUTTER.

Application led January 19, 1926. Serial Io. 82,320.

tively forcing these cutters outwardly forengagement with the wall.

A further and more specific object of the invention is the provision of a control mechanism for the cutters including a frangible pin and novel tripping mechanlsm by means of which this frangible pin ma be broken to permit the cutters to move to t eir operative position.

A still further object of the invention is to provide a device of this character which, if desired, may be readily employed with a piston mechanism for shifting the cutters.

A further object of the invention is to provide a device of this character which may be emplo ed for cutting casing below one of the relatively small openings provided by the tool joints of modern rotary well drilling apparatus.

These and other objects I attain by the construction shown in the accompanying drawings, wherein for the purpose of illustration is shown a preferred embodiment of my invention and wherein Figure 1 is a view showing a casing cutter constructed in accordance with my invention in position within a well casing prior to tripping thereof;

Figure 2 is a sectional view through the casing and tool joint showing the manner of guiding the casing cutter;

Figure 3 is a vertical sectional view showing the position assumed by the parts after the device has been tripped;

Figure 4 is a vertical sectional view show-` ing a slightly modified tripping mechanism. Referring'vv now more particularly to the drawings, the cutter consists essentially of a member 10 tubular at its upper end, as indicated at` 11, and having a solid lower end 12 rounded at its extremity, as indicated at 13, for engagement in the bore 14 of a tool joint 15. The tubular upper end is engaged with a coupling element lfincluding a disk 17 closing the upper end of the tube and having a central bore 18.

The upper end of the solid portion 12 of the element has formed therein a vertical diametrically extending slot 19 openlng through the wall ofthe solid portion and also through the upper end thereof. Pivoted upon a pin 20 extending diametrically of the lower end of the tubular portion 11 and at right angles to the slot 19 are a pair of cutter blades 21, each having acasing cutting extension 22 in its lower outer face and each having a shank 23 engaging the pin and having its upper end provided with beveled faces 24 and 25 at right angles to one another. Slidably mounted within the tubular portion is a piston 26, the stem 27 of which is directed through the bore 18 of the coupling 16.- Any suitable means may be provided for preventing rotation of this piston. In the present instance, the stem at its passage through the bore 18 is splined to the bore, as indicated at 28. The lower surface of this piston has inclined faces 29 and 30.

The blades 21 are of such weight that the normally assumeby gravity a position suc as illustrated in Figure 1 and in which their cutting faces 22 are withdrawn and spaced apart a distance less than the diameter of the element so that the blades are concealed.

While in this position, the beveled faces 24 of the shanks 23 of the blades are each opposed to one of the beveled faces'29, 30, of the lower face of the piston. Accordingly, if the piston is forced downwardly, these beveled faces will be engaged by the correspondingly beveled faces of the piston and the piston will act as a wedge swinging the upper ends of the shanks toward the center of the tubular section 11 and the lower ends thereof outwardly so that the cutting faces 22 are brought into engagement with `the casing which is generally indicated by the character C. As4 the pressure continues and the device is rotated, these faces cut the casing Severin the same. When the severing is complete| the cutting faces, the upper surfaces of which are hooked, as at 31, will be forced outwardly beneath the casing and will serve to support the severed section of the casing during its withdrawal from the well. The

outward movement of the blades is limited by engagement of the beveled face 25 thereof with either the face 29 or 30 of the piston.

For example, the blade whose shank face 24.- o

25 with the face 29 of the piston. The solid extension 12, as hereinbefore stated, is adapted for engagement in the bore of a tool joint. Since these cutting operations are usuall necessary due to` jamming or sticking o tools within the bore, it is, of course, often desirable that the cutting be accomplished immediately above or below the tool joint and in the former event, the tool joint is available as a guide for steadying the lower end` of the cutter. In event it 1s desired to cut the casing below the 4tool joint, it will be obvious that the cutters being normally concealed within t-he member 11 may be passed with this member 11 through the tool joint lbore 14 and the cutters expanded after they have passed therethrough. It will b'e noted that the entire device including its connect-ions with its support is of less size than the internal diameter of this tool joint. The entire cutter is rotated through the tubing T, as shown.

Either of two methods may be employed for securing projection of the cutters at the desired point. In Figure 3, the rod 27 is shown as having arranged thereon between the coupling 16 and the piston, a spring 32 which constantly urges the piston downwardly. At its upper end, this rod is provided with a head 33. The lower section 34 of the tubing T has directed therethrough and through the head 33 a rangible pin 35. Pivoted to .the head 33 is a latch 36, the upper end of which is hooked outwardly and normally passes through an opening 37 formed in the casing. Its projection .through this opening is assisted by a spring 38 secured to the casing section 34 and abutting the latch. i I In this form of device, the tubing T having at its lower end the casing cutter is lowered to the proper depth. The projection of the latch 37 is suiiicient that this latch engages against the wall of the tubing. A relatively sharp upper end 39 is formed on the projecting end of the latch and after the proper position is assumed, the tubing T is jerked upwardly with the result that this point engages in the well casing and applies pressure to the head 33 and frangible pin 35 so that the pin 35 is broken. The s ring 32 may then act to urge the piston 26 own pardl and expand the cutters as hereinbeore ure v4, the stem 27 has a spring 40 similar to the spring 32 mounted thereabout above the coupling 16 and at its upper end is provided with a piston 41, the ylower section 34a of the tubing being inthe form of a cylinder.

I -n this type of construct-ion, operation is had yby pumpingv through the tubing T so that pressure 1s applied to the piston 41 and the pistons 41 and 26 force downwardly against the-action of the spring 40 to expand the cutters. After the cutting operation is comescribed. In the form shown in Fig-I pleted, the pressure ma be removed and the cutter and tubing wit drawn through the well casing. v

It will be obvious that the structure employed in the construction ofthe cutter itself enables ready. interchangingof the two operating mechanisms above described and -the 'uppers end of the member and including a disk closing the upper endof the tube, the member being provided with a diametrical slot, la pair of blades pivoted within the member and projectable through the slot, said blades having shanks extending upwardly into the tubular portion and having upon their upper ends oppositely pitched portions, a piston reciprocable within the tube and having on its lower face oppositely pitched portions forv engagement with the oppositely pitched portions of the upper,

ends of said shanks and means normally holding said piston out of engagement with the Shanks of the blades.

2. In a casing cutter, a member having a tubular upper end and a solid lower end provided in the upper end of said solid lower end with a diametrically extending slot, blades pivoted within the slot having body portions projectable through the ends thereof, said blades normally being disposed by gravity in a substantially vertical position,

each blade having at the upper end of the shank thereof oppositely beveled faces, a pistonl movable within the tubular upper end of the member and having upon its lower surface oppositely beveled faces, each of which is adapted to engage one of the beveled faces of one of said Shanks when the piston is lowered to thereby wedge the upper ends of saidshanks toward a common center and cause the bottom ends of the" Shanks to move outwardly, the other beveled faces of said shanks coming into engagement with the beveled face of the piston primarily engaged bythe first named beveled face of the other of the shanks to thereby limit I tubular upper end and a solidilower .end

provided in the upper end of said solid lower end with a diametrically extending slot,

blades pivoted within the slot having 'body` portions projectable through the ends thereof, said blades normally being disposed by gravity in a substantially vertical position, each blade having at the upper end of the shank thereof oppositely beveled faces, a' piston movable within the tubular upper end of the member and having upon its lower surface oppositely beveled faces each of which is adapted to engage one of the beveled faces of one of said Shanks when the piston is lowered to thereby wedge the upper ends of said Shanks toward a common center and cause the bottom ends of the shanks to move outwardly, the other beveled faces of said Shanks coming into engagement with the beveled face of the piston primarily engaged by the first named beveledI face of the other of the Shanks to thereby limit movement of the shanks at a predetermined position and accordingly limit the projection of said blades, means for urging the piston into engagement withfthe Shanks and means for holding the piston out of engagement with the first named means until a predetermined pressure has been applied to the piston.

4. In a casing cutter, a member having a tubular upper end and a solid lower end provided in the upper end of Said solid lower end with a diametrically extending slot, blades pivoted within the slot having body portions projectable through the ends thereof, said blades normally being disposed by gravity in a substantially vertical position, each blade having at the upper end of the shank thereof oppositely beveled faces, a piston movable within the tubular upper end of the member and having upon its lower surface oppositely beveled faces, each of which is adapted to engage one of the beveled faces of one of saidshanks when the piston is lowered to thereby wedge the upper ends of said shanks toward a common center and cause the bottom ends of the Shanks to move outwardly, the other beveled faces of said Shanks coming into engagement with the beveled face of the piston primarily engaged by the first named beveled face of the other of the Shanks to thereby limit movement of the Shanks at a predeterminedl position and accordingly limit the projection of said blades, means for urging the piston into engagement with the Shanks, a. Stem for the piston, a frangible pin operatively engaged with the stem and with tubing supporting said member, a blade operatively pivoted to the upper end of the stem, the tubing having an opening in the side wall thereof, the blade having a hooked end projecting through said Side wall, the tubing having a spring engaging the blade to insure such protrusion, the protruding upper end of the blade adapted for engagement with the casing to be Severed to prevent upward movement of the tubing and member until said pin Shall be broken.

5. A casing cutter comprising a member having a Slot, a pair of blades pivoted within the member and projectable through the ends of the slot to engage the walls of the casing, the blades having oppositely pitched portions, a spring-pressed piston having oppositely pitched portions to engage the oppositely pitched portions of the blades and force the blades outwardly for engagement with a casing to be cut when said piston moves under the iniiuence of its spring, a frangible pin holding said piston against movement with relation to the member and a trip element operatively pivoted to Said piston projecting through a slot formed in the wall of the member to engage the casing and prevent relative movement of the casing and member in one direction until the pin is broken and the piston released for movement.

In testimony whereof I hereunto aiiix my signature. v

' ROBERT A. LINCOLN. 

